HPB P16 How relevant are additional histological features when predicting five-year recurrence/survival rates afterpancreatoduodenectomy for ampullary adenocarcinoma? Results from the Recurrence After Whipple’s (RAW) study

Abstract

Abstract Background Providing they have an appropriate performance status, patients with ampullary adenocarcinoma (AA) may be offered pancreatoduodenectomy (PD) with curative intent. Aggressive histological tumour characteristics are known to correlate with poor long-term outcomes. This study aimed to quantify how peripancreatic fact invasion (PPFI), perineural invasion (PNI), microvascular invasion (MVI) and lymphatic invasion (LI) correlate with five-year recurrence and five-year survivalrates. Methods Data were extracted from the Recurrence After Whipple’s (RAW) study, a multicentre retrospective cohort study of outcomes of PD performed for pancreatic head malignancy (29 centres in 8 countries, n=1484). Patients with histologically confirmed AA were identified and compared by their PPFI, PNI, MVI and LI statuses. Fisher’s exact test was used for the comparisons. Results A total of 394 patients (26.5%) had AA confirmed. Incidence rates of PPFI, PNI, MVI and LI were 37.8%, 46.1%, 45.2% and 58.6%, respectively. Five-year recurrence was significantly higher in patients demonstrating PPFI (58.9% vs 34.3%, p=0.0005), PNI (56.6% vs 34.0%, p=0.0001), MVI (60.2% vs 34.2%, p<0.0001) and LI (54.7% vs29.2%, p<0.00001). Five-year survival was significantly lower in patients with PPFI (29.4% vs 62.9%, p<0.0001), PNI (40.4% vs 64.8%, p<0.0001), MVI (43.0% vs 61.3%, p=0.003) and LI (44.1% vs 65.0%, p<0.0005). Patients with PPFI, PNI, MVI and LI were significantly more likely to have histological T3-4 disease (vsT1-2, all p<0.0001). Conclusions In our multicentre study of AA patients who underwent PD, less than half had histological evidence of PPFI, PNI or MVI, but a majority had LI. All of these features were associated with increased recurrence and reduced survival rates. However, this likely reflects the fact that these features all correlate with more advanced histological disease.